For most consumers of pop culture, fandom is a lower-case concern. They are “fans” in the sense that they may like a particular movie, TV show, band, or personality but don’t think much about it when not experiencing it firsthand. Capital-F Fandom is something else altogether. It goes beyond “like” or even “love” and straight to “devoted.” Their Fandom is all-consuming, a jumping-off point for a deep dive into fan fiction, convention-attending, recap-writing, role-playing, costume-making, language-learning, and more. There is a passion to this kind of Fandom that binds enthusiasts in the manner of people who share a secret — this secret just happens to be shared with millions of others.

Vulture has scanned the great plains of pop culture, weighing passion versus mere popularity to decide the 25 Most Devoted Fans of entertainment, which kicks off our weeklong exploration of all things Fandom. (Get a badge for each fandom here to use as your Twitter or Facebook profile pic, or for your phone wallpaper.) It’s important to underscore that this list is not about mere numbers — it’s about fervency. The Transformers movies have made billions worldwide, but if Paramount announced they weren’t going to make another one, nary a pen would be put to paper in protest. Meanwhile, Community’s audience has never tipped over 5 million, but nearly every viewer is a true Fan who is poised to storm the NBC gates if the network decides never to air the limbo’d fourth season. The followers of the franchises, musicians, TV shows, authors, and directors on this list made it because of their supercharged, multipronged dedication, whether they be legion or a small guerilla troop. (Also: We limited it to fans of active pop-culture phenomena, so no Beatles. Though the Harry Potter saga is technically over, it still remains organic through its theme park, upcoming Blu-ray releases, and general obsession with author J.K. Rowling, as evidenced by the recent furor over the non-Potter-ness of her novel The Casual Vacancy.)

Before you jump in to see if your passion clique made it, an important Fan alert: Next week, Vulture will be following up this countdown with our list of the Most Devoted Individual Fans. Think you belong on it? Then tell us a story below in the comments about the most extreme thing you’ve ever done in the name of your love for your favorite entertainment. They can be hilarious, emotional, or superhuman — we’ll select and highlight the best ones for next week’s feature. Help make sure your Fandom is represented!